There has been fierce debate recently over whether the original “caveman” diet was one of heaps of bloody meat or fields of greens. New findings suggest that some of our early ancestors were actually quite omnivorous. But subsequently, our line and an ill-fated group of hominins developed very different dietary strategies. One chose meat while the other moved toward more plants.
The hominin Australopithecus, which lived from about 4 million to 2 million years ago, is presumed to be a common ancestor of both the Homo lineage, which emerged some 2.3 million years ago and gave rise to us, and to the Paranthropus genius, which is first documented about 2.7 million years ago and died out about 1 million years ago. Some have attributed the extinction of Paranthropus to an inflexible diet or limited territory, especially in the face of climactic changes.
A team of researchers led by Vincent Balter, of École Normale Supérieure de Lyon, decided to probe into some of these debates. They used lasers to analyze the enamel from fossilized teeth belonging to Australopithecus africanus, Paranthropus robustus and early Homo specimens, which were all from southern Africa. By assessing ratios of calcium, barium and strontium as well as the number of strontium isotopes, the team was able to deduce both diet and the size of the area that these individuals ranged over. The findings were published online August 8 in Nature (Scientific American is part of Nature Publishing Group).